Large diameter, CNC-machined front sight that incorporates a light gathering fiber optic rod for high visibility and faster sight acquisition, even in poor lighting. Universal design fits most shotguns. Gunsmith installation may be required. Fiber diameter is .100" and Fiber length is 0.5". Note: Includes thread adapters for 6-48 / 3-56 / 2.6mm / 5-40 / 3mm threads